Breakaway coupling for fluid conduits



Jan. 19, 1954 E. F. BRUNING 2,666,656

BREAKAWAY COUPLING FOR FLUID CONDUITS Filed Dec. 20, 1950 2 Sheets-Sheet1 Jan. 19, 1954 6 E. F. BRUNING BREAKAWAY COUPLING FOR FLUID CONDUITS 2Sheets-Sheet 2 Filed Dec. 20, 1950 INVENTOR.

rant/k fll'i'IF/VEIS Patented Jan. 19, 1954 *UNITED STATES PATENT orriceBREAKAWAY COUPLING FOR- FLUID CONDUITS Earl F. Brun'ing, Lincoln, Ncbr.

Application December 20, 1950, Serial No. 201,745

3Claims. (Cl. 2285-35) This invention relates to a fluid conduitcoupling, and more particularly to an automatic break-away coupling foruse in installations where elements or mechanisms between which thefluid conduit extends are subject to possible unintentionaldisconnection.

In my prior patent, No. 2,512,999, granted June 27, 1950, I havedisclosed a novel type of fluid coupling which possesses substantialadvantages over prior structures in numerous ways, such as ease ofcoupling and uncoupling, minimum interference with the flow of fluidwhen the device is coupled, etc. In order to uncouple the elements, asleeve is moved axially against the tension ofa spring to releaselocking balls which normally connect the coupling nipples with thelocking sleeve. This arrangement of parts and the control means thereforis highly advantageous in most installations where a coupling'of thischaracter is used.

In certain other installations; it is highly de sirable to provide acoupling which is automatically disconnected under certain conditions.For example, in many. farm implement power combinations, a tractor isconnected through a suitable hitch with a'following implement hav-- ingparts adapted to be controlled hydraulically Irom the dri'vers seat ofthe tractor, and to this end, a hose coupling is provided to conveyhydraulic fluid to the implement. In such installations, there is alwaysdanger of disconnection of the tractor from the implement due to failureof the hitch in some manner or due to overloading of the hitch, forexample when a plow strikes an obstruction, and when this occurs, thereis inevitable breakage of the fluid line.

In aircraft structures, it is the common practice to install a flre wallin a needle rearwardly of the engine to act as a fire stop in the eventthe engine catches fire. The fuel supply line for'the engine extendsthrough such fire wall, and in the occasional cases wherein engines tearloose from their mountings, the fuel lines are ripped out and fuel flowsfrom the source through the pipe line and constitutes an extremelyserious flre hazard.

An important object of the present invention is to provide a novel typeof coupling which,

when the parts thereof are in coupling engagement, provides for the freeflow of fluid there'- throughtbut which, upon-the transmission of apulling iorceincident to the disconnection of the units or mechanisms towhich thefluid conduit is connected, is automatically released to discnn he retried c ndu t withou d ma to 2 the coupling or the pipe lines,and wherein the previously coupled conduits are instantly sealed toprevent the flow of fluid therefrom.

A further object is to provide a novel coupling of the characterreferred to having acoupling sleeve or corresponding unit fixed againstaxial movement with relation to the structure by which it is carried,and which is so constructed and arranged with relation to the othercoupling elements that when a pull is exerted on one of'the coupledconduits, the two conduits are substan tially instantly fullydisconnected and closed against loss of fluid therefrom.

A further object is to provide a coupling of the type referred towherein the coupling sleeve structure or the like is mounted withrespect to the supporting structure, which fixes it against axialmovement, in such manner as to provide for its universal movement,thereby particularly adapting the structure for use in an airplaneengine nacelle so that in the event an engine tears loose, the lockingsleeve member of the coupling is adapted to swing in accordance with thedirection of pull of the engine as it tears loose from its mountings,thus insuring the transmission of an endwise pull to the fluid lineleading to the engine, whereby the coupling will be instantlydisconnected and the conduit sections closed against loss of fluid,thereby eliminating 'a serious fire hazard.

Other objects and advantages of the present invention will becomeapparent during the course of the following description.

In the drawings, I have shown one embodiment of the invention. In thisshowing,

Figure 1 is a fragmentary plan view of a portion of an airplane, partsbeing broken away and parts being shown in section generally to indicatethe mounting of the present device in the flre wall of the enginenacelle,

Figure 2 is'a fragmentary sectional view taken substantially on line =2-Z of Figure 1, showing a portion of the flre wall, and pipes leading tothe coupling being omitted and the parts of the device being shown infully coupled relation,

Figure 3 is a similar view taken with the move v able parts shiftedtoward the left and with the and with the left hand nipple returned tonormal position,

Figure 5 is a section on line 5--5 of Figure 2, and

Figure 6 is a similar .view on line 66 of Figure 2.

Referring to Figure 1, the numeral Ill designates the fuselage of aconventional airplane having the usual wings each provided with at leastone engine nacelle. One such nacelle is shown in Figure 1 and indicatedby the numeral l2, and in such nacelle, a conventional engine isdiagrammatically shown in dotted lines and indicated by the numeral l3and connected to a conventional propeller l4. Within the nacelle isarranged a fire wall l5, the normal purpose of which is to prevent thespread of fire in the event the engine catches happens.

In the use of the present invention in airplanes, the fire wall I5 isused as the supporting means for the coupling, indicated as a whole bythe numeral 29. It will become apparent that for other installations,such as with tractor-implement combinations, the member i5 may be afire, as occasionally The nipple 35 slidably fits within the adjacentend of the enlargement 42. The inner end of the nipple 35 is reduced asat 50 axially to fit within a reduced bore 5| in the enlargement 22. Theadjacent portion of such enlargement is provided with an internal groove52 in which is arranged an O-ring 53 to seal against fluid leakagebetween the nipples when the device is coupled, as will be apparent.

Each nipple is provided with an internal bore 54, the inner extremity ofwhich curves inwardly as at 55 to form a valve seat in a manner to bedescribed. Within this bore 54 is arranged.

' is carried by each stem BI and is provided with sup orting bracket riidly connected to the tractor or to the implement, de ending upon whichconduit section is to be released, as will become more apparent below.

In the embodiment of the invent on illustrated, the coupling comprises acontrol sleeve 2| shown as having its outer surface 22 formed as asection of a sphere arran ed in a socket 23 formed of complementarysections 24 and. 25 bolted as at 26 to the fire wall l5. It will beapparent that the sleeve 2| is free to rock on the center of thespherical surface 22 while being fixed a ainst all movements except suchrocking movement.

The sleeve 2| is provided with an axial bore 28 with which communicatesan annular internal groove 29 having radially inwardly diverging endwalls for a purpose to be described. This groove is arranged adjacentthe left hand end of the bore 28 is viewed in Fi ure 2, and at the oposite end of such bore is formed a tapered positive positioningshoulder for a purpose to be described. To the ri ht of such shoulder,the sleeve 2| is provided with a second axial bore 3| for a purpose tobe described.

The elements to be cou led comprise two nipples indicated as a wholerespectively by the numerals 35 and 36. These nipples are provided withfittin s 3' threaded therein for connection through suitable coactinunion members with pine or conduit sections 38 and 39 (Figure 1). The niple 35 is of an external diameter adapted to slide within the minordiameter of the shoulder 35. To the left of such shoulder, the n pple'35 is annularly enlarged as'at 42 to slidably fit within the bore 28.Such enlarged portion of the nipple 3.5 has its ri ht hand end, asviewed in Figure 2, tapered as at 43 to provide a shoulder enga eablewith the shoulder 30. The enlar ement 42, intermediate its ends. isprovided with circumferentiallv spaced rad ally outwardly tapered o en ns 45 each receiving a locking ball 46 of slightly larger diameter thanthe m nimum diameter of the openings 45. The balls 45 are adapted underconditions and for a reason to be described to move radially outwardlyinto the groove 29; In the normal nositionof the parts, when coupled,the balls 46 are engageable in a radially outwardly taperedannular-"groove 48 formed in the outer surface of the nipple 35.With'the balls 46 arranged as shown' in Figure 2, the nipples 35 and 36are fixed against axial movement with respect to each other.,

an O-ring 64 forming a valve element engageable with the associated seat55. Each valve 52 is provided with an axial projection 55, and theprojections of the two valves are engageable with each other when thedevice is coupled to maintain the valve elements 64 oif their seatsagainst the tension of compression springs 65.

A compression spring 68 has one end seated against the inner extremityof the bore 3| and has its opposite end engaging the nut 69 of theassociated fitting 31. This spring obviously functions to urge thenipple 36 and associated elements toward the right to maintain the partsin their normal coupling positions as shown in Figure 2.

Operation In assembling the coupling, the socket mem bers 24 and 25obviously are brought into position from opposite ends of the sleevemember 2 whereupon they are secured together and fixed to the support |5by the bolts 26. The support l5 in the case of an airplane engine fuelline will be the fire wall shown in Figure 1. In a towed equipmentinstallation, the member |5 will be a stationary bracket or the like,carried either by the tractor or the implement vehicle.

As will become apparent below, the mounting shown in Figure 2 is suchthat if the fitting of the nipple 35 leads to the tractor, the supportl5 will be connected to the implement vehicle. If the fitt ng 31 of thenipple 36 is to be connected to the tractor, the support l5 will befixed to the tractor so that upon disconnection of the implementvehicle. from the tractor by accident, the resultant pull on the nipple35 will disconnect the parts. In the case of the airplane installationshown in Figure 1, the support l5 will be the fire wall, the pipe 39from the fitting 31 of the nipple 36 will lead to the source of fuelsupply, while the pipe 38 will lead to the engine so that if the lattertears loose from its mounting, the pull transmitted by the pipe 38 tothe nipple 35 will uncouple the parts, and this operation is describedin detail below.

In assembling the coupling elements, the nipple 36 is inserted throughthe sleeve member 2| from the left end thereof as viewed in Figure 2,the shoulders 30 and 43 being brought into engagement with each other.The coil spring 68 is then slipped over the nipple 36,'whereupon thefitting 31 with the cage 58, valve 62 and spring '56 in positiontherein, is screwed into the nipple 35. When 'thes'e'partsare assembled,the spring 68 will be loaded,'thus tending resiliently to hold theshoulder 43 in engagementwith the shoulder 30;

It will be apparent that when the nipple 36 is inserted in the mannerstated, the balls 46 will be "in position in the openings 4-8 and theearing .53 will be in position .in thewannular groove .52. The mainparts of the device are then completely assembled ready for the couplingof the nipple 35. The elements of this nipple are assembled in amanner'wliich will be obvious, and prior to the coupling of the n pples,both valves 62 will be closed as shown in Figure 4;. The nipple 35 iscoupled with respect to the nipple 33 merely by sliding it axially tothe right as viewed in Figure 2 while forcing the nipple 36v to the leftto bring the balls 46 into registration with'the groove 23. Theshoulder'at the left handend of the reduced n pple portion '5 I, undersuch conditions, moves the balls 4'3 outwardly into the groove 29,whereupon the nipple "35 may be moved to the right to align the grooves29 and '48transversely. The balls 35 are then free to move radiallyinwardly to clear the groove '23, whereupon the nipples 35 and 35 arefree to move to the right as a unit to the fully coupled position shownin Figure 2.

During such coupling movement, the point will be reached in which theaxial projections 55 of the valves contact with each other, andthereafter the completing of the coupling operation unseats the valves62, thus providing for the free passage of fluid through the coupling.In the case of an airplane installation as shown in Figure 1, the partsremain coupled and fuel flows from right to left as viewed in Figures 1and 2 to the engine 13. In the event of the accidental loss of an enginedue to its breaking loose from its mountings, a pull will be exerted onthe pipe section 38 and this pull will be transmitted through theassociated fitting 31 to the nipple 35. In the event this pull is not indirect alignment with the axis of the device with the parts positionedas shown in Figure 2, the angularity of the pull will result in theswinging of the coupled elements and the sleeve member 2| whereby thecoupled elements will assume positions in axial alignment with the lineof pull transmitted to the nipple 35.

Upon the occurrence of such a pulling force,

the nipple 35 will move to the left and its movement will be transmittedthrough the balls 46 and the walls of the openings 45 to effect movementof the nipple 35 to the left against the tension of the spring 58. Thismovement of the nipple 35 continues until the balls become transverselyaligned with the groove 29, whereupon the slope ing right hand sides ofthe openings 45, as viewed in Figure 2, will cam the balls 45 outwardlyinto the grooves 29, thus unlocking the nipple 35 from the nipple 36, asshown in Figure 3. Slight continued movement of the nipple 35 to theleft, for example as shown in Figure 3, releases the valves 62 formovement to closed position by the springs 65. Both pipes 38 and 33accordingly will be closed against loss of fluid, thus substantiallyeliminating the usually existing fire hazard in an accident of thistype.

After the nipples have been released, the nipple 35 continues its freemovement to the left as in Figure 4 and it will be wholly disconnectedfrom the coupling device and free to move with the engine. The spring 68then snaps the nipple 35 back to its normal position as shown in Figure4 with the shoulders 30 and 43 in engagement with each other. maticallycut oil and all open ngs throughithe fire wall [5 sealed, andaccordingly, it will'be'japparent that the present invention provides amaterially increased factor of safety in the operation of airplanes.

Thus the fuel line 39 will be auto- The O-n'ings =54learried bythevalves formeffective liquid seals when engagement with their 'seats55,while the o-ring 53 prevents any loss of fluid due to seepage betweenthe inner-ends-of the nipples 35 and 36. the normal operation of theparts as shown in Figure -2, therefore, the valves 62 aremaintained"open for the free flow of liquid through the coupling, and anynegligible leakage of liquid which otherwise would occur is prevented bythe "Cl-ring 53. The engaging surfaces :of the parts are preferablyaccurately machined so that any leakage which would occur in the.absence of the =O-ring 53 in any event would be negligible, Theoperation of automatically uncoupling the parts in other installations,such as the use of the coupling for hydraulic lines between tractors andfarm "implements, will be the same as described above. Assuming that atractor hitch connecting the vehicles accidentally becomes uncoupled orbreaks, thus releasing the tractor from the implement vehicle, theexertion of a pull on the nipple 35 will instantly result in theuncoupling of the elements in the manner described above. In atractor-implement combination, it usually is unnecessary to universallysupport the sleeve member 2|, in which case the members 24 and 25 can beconsidered integral with the sleeve member and suitably connected to thesupport [5. The universal mounting is preferred, however, to positivelyassure the uncoupling of the parts under conditions such as thosedescribed, if the pulling force transmitted to the nipple 35 is not inexact alignment with the axis of the device in its normal position.

I claim:

1. In combination with an engine nacelle, a fire wall in said nacellehaving an opening, a coupling structure completely filling said opening,said'coupling structure comprising a sleeve, means mounting said sleevefor universal movement in said opening, a pair of telescoped nipples insealing relation axially slidable in said sleeve and occupying normalpositions relative to each other and relative to said sleeve influid-flowing relation, said nipples being adapted for connection withpipe sections for the flow of fiuid therethrough, locking means fixingsaid nipples against relative axial movement when in said normalpositions, means for releasing said locking means from one of saidnipples upon the transmission of a pull thereto moving said nipples in adirection away from their normal positions relative to said sleeve, anormally open valve in the other of said nipples, and meansautomatically closing said valve when said nipples are disconnected.

2. In combination with an engine nacelle, a fire wall in said nacellehaving an opening, a

. coupling structure completely filling said opening, said couplingstructure comprising a sleeve, means mounting said sleeve for universalmovement in said opening, a pair of telescoped nipples in sealingrelation axially slidable in said sleeve and occupying normal positionsrelative to each other and relative to said sleeve in fluid-flowingrelation, said nipples being adapted for connection with pipe sectionsfor the flow of fluid therethrough, locking means fixing said nipplesagainst relative axial movement when in said normal positions, means forreleasing said looking means from one of said nipples upon thetransmission of a pull thereto moving said nipples in a direction awayfrom their normal positions relative to said sleeve, normally openvalves in 7 said nipples, andmeans automatically closing said valveswhen said nipples are disconnected, 3

3. In combination with an engine nacelle, a fire wall in said nacellehaving an opening, a coupling structure completely filling said opening, said coupling structure comprising a support mounted'in saidopening and secured to said fire wall and provided with an internalsurface formed as a section of a sphere, a sleeve having an externalspherical surface fitting within said support to be universallysupported thereby, a pair of telescoped nipples in sealing relationaxially slidable in said sleeve and occupying normal positions relativeto each other and relative to said sleeve in fluid-flowing relation,said nipples being adapted for connection with pipe sections for theflow of fluid therethrough, locking balls fixing said nipples againstrelative axial movement when in said normal positions, means forreleasing said balls from one of said nipples upon the transmission of apull thereto moving said nipples in a direction away from their normalpositions relative to said sleeve, normally open valves in said nipples,and means automatically closing said valves when said nipples aredisconnected.

EARL F. BRUNING.

References Cited in the file of this patent UNITED STATES PATENTS

